LR. Lydekker—Note on the Ichthyopterygia. dll 
8. Femur longer, with trochanteric ridge less developed. 
*9. IonrHyosauRus (?) ovatts, Phillips. Kimeridge Clay, Eng. 
10) ss (2?) TrHyrEosPponDYLUs, Phillips. KimeridgeClay, 
England. 
Syn. (?) I. brachyspondylus, Owen. 
(?) I. thyreospondylus, Owen. 
11. IchTHYosauRUS LEPTosponDYLUS, Wagner. Kimeridgian, 
: Bavaria. 
12. IcurHyosaurus ENTHECIODON, Hulke. Kimeridge Clay, 
England. 
15. IchrHyosauRuS TRIGONUS, Owen. Kimeridge and Oxford 
Clays, England. 
Syn. (?) I. posthumus, Wagner. Kimeridgian, Bavaria. 
*14, IcurHyosaurus (?) pizatatTus, Phillips. Kimeridge and 
Oxford Clays, England. 
*15. IcHTHYOSAURUS HILDESIENSIS, Koken. Neocomian, North 
Germany. 
b. Typical subgrowp.—Roots of the teeth without cement ; humerus 
without prominent trochanteric ridge. 
16. IcnrHyosaurus communis, Conybeare. Low. Lias, England. 
te Fa BREVICEPS, Owen. is re 
18. 3 ConyYBEARI, n.sp., nobis. __,, 
19. x INTERMEDIUS, Conybeare. _,, a 
B.—Longipinnate Group.—Pectoral limb with the third digit con- 
taining one longitudinal row of bones and a single centrale; 
radius nearly square, and usually with notched anterior 
border. 
a. Acutirostrine subgroup.—Teeth small and cylindrical, coracoid 
without posterior notch ; head of humerus oblong. 
20. IcHTHYOsAURUS INTEGER, Bronn. Up. Lias, Wiirtemberg 
and (?) England. 
21. IcHrHyosAURUS AcUTIROSTRIS, Owen. Up. Lias, Europe. 
Syn. I. longipennis, Mantell. 
I. microdon, Wagner. 
I. quadriscissus, Quenstedt. 
I. Zetlandicus, Seeley. 
I. longifrons, Owen. 
b.—Tenuirostrine subgroup.—Teeth small and cylindrical ; coracoid 
with posterior notch; head of humerus triangular. 
22. IcHTHYOSAURUS TENUIROSTRIS, Conybeare. Lias, Europe. 
Syn. I. grandipes, Sharpe. 
23. IcnTHyosAuRUS LATIFRONS, Konig. Lias, England. 
Syn. I. longirostris, Owen. 
(?) I. longirostris, Jager. 
c. Platyodont subgroup.—Teeth large, either cylindrical or cari- 
nated ; coracoid without posterior notch; head of humerus 
triangular. 
24. IcnTHYOSAURUS LoNCHIODON, Owen. Low. Lias, England. 
Zon 3, s PLATYODON, Conybeare. Low. Lias, England. 
Syn. Ichthyosaurus giganteus, Leach. 
